Cogito, ergo sum


Graph of function

1. Purpose of the program

The program accepts data from the user, calculates the values of the formula: Y(X)=a1*sin(b1*X)+a2*sin(b2*X)+a3*sin(b3*X), outputs the values as a table and builds a graph.

1.1. Input data

The user must enter the following parameters:

1.2. Output data

At the output, the program will show the following results:

2. Project structure

File name The contents of the file
GR_HEAD.H List of connected libraries, declarations of global variables, class prototype Coordinate function prototypes
GR_MAIN.CPP The list of connected files and the main() function, in which the main algorithm of the program is executed(рис. 1.)
GR_PROC.CPP Description of the Coordinate class and definitions of functions related to processing data of this class
GR_INTRF.CPP Definitions of auxiliary functions of the program display of the graph on the screen
GR_RW.CPP File write and read function definitions

3. Алгоритм программы

The algorithm of the main menu is shown below:

Pic. 1. Algorithm

4. Compilation

The program code was written in C++ using a programming environment Borland 3.1 The choice of this development environment was determined by the principle of “necessary and sufficient”. The result of the compilation will be a console application.

5. Working in the program

Let’s look at the interaction with the program on a small example.

5.1. After the launch, the main menu of the program will be available.

Pic. 2. Main menu

5.2. Entering parameters

Press «F2» to open the window «Enter parameters» and enter the values X_0, X_k, ∆X, a_1, b_1, a_2, b_2, a_3, b_3(pic.3.)

Pic. 3. Entering parameters

Press «Enter».

5.3. Table of results

After that, we will see a table of the values of the Х and Y functions: Y(X)=a1*sin(b1*X)+a2*sin(b2*X)+a3*sin(b3*X)

Pic. 4. Table of results

The same table opens when you press «F3» in the main menu. You can view the entire table using the keys «↑» and «↓».

5.4. Geaph of the function

After pressing «Enter» or «Esc» the graph of the function Y(X) appears.

Pic. 5. Graph of the function

(available by clicking «F4» in the main menu). Pressing any key returns us to the main menu..

5.5. Editing a table

To edit the data in the main menu, press the key «F5».

Pic. 6. Editing a table

The coordinate that is active for editing is highlighted in red.

To select a different coordinate, press the keys «↑», «↓», «←», «→» or «Tab».

Pic. 7. Editing a table 2

To start editing, press the «Backspace» key and enter the required value.

Pic. 8. Editing a table 3

To save this value, press «Enter». To exit the edit mode, press «Enter» again.

A new graph of the function will appear in front of us:

Pic. 9. New graph of the function

5.6. Save the results

To save the data to a file in the main menu, press «F6»

Pic. 10. Save the table

As a result, a file with the coordinates of the specified graph will appear in the program directory

Pic. 11. New file with the coordinates

You can edit the file in notepad, save it, and then read it.

5.7. Read the results

To read data from a file, in the main menu, press «F7», enter the path to the file and press «Enter».

Pic. 12. Reading the file

A graph will appear in the window with the changes that we made in the file:

Pic. 13. Updated graph of the function

6. Exit

By pressing the «F12» key, the program is terminated normally.

Thank you for your interest! :)

tags: c++ - studies